Removable cartridge disk drive with an integral head loading ramp, air filter and removable cartridge door safety stop

ABSTRACT

A disk drive (50) having an integral apparatus (280) for ensuring that the door (68) of a removable cartridge (52) is properly opened, that the heads (286) of the disk drive (50) are properly unloaded onto the disk (256) in the cartridge (52) and that air filters (296) are appropriately positioned. The integral apparatus (280) includes an integral member (300) which provides a door safety stop (302) for ensuring that the door (68) of the cartridge (52) is properly opened should the door position reach a predefined threshold, and for preventing the further reception of the cartridge (52) into the disk drive (50) should the door position not reach the predefined threshold. The integral apparatus (280) further includes a ramp device (304) for receiving the actuator arm (282) onto which a head (286) is fixed and for unloading the head (286) onto the disk (256) and a base (294) for holding an air filter (296) relative to the door safety stop (302) and the ramp device (304) apparatus.

FIELD OF THE INVENTION

The present invention is directed to a disk drive and in particular adisk drive which will accept a removable cartridge which houses memorymedia for communication with the disk drive.

BACKGROUND OF THE INVENTION

At present the industry trend is to provide for greater memory capacityin a reduced form factor at a lower cost with a lower energyconsumption. This trend is driven by the increased demand for portable,lap top, notebook and palm top computer configurations which can beeasily transported to a desired work site. The desired memoryconfiguration would include, for example, a magnetic or optical harddisk drive as such drives store a considerably higher amount of datathan a floppy disk drive and can access that data at a ratesubstantially in excess of that of a floppy disk drive.

With respect to hard disk drives, there are two major types. The firstis a hard disk drive with the memory media or magnetic disk permanentlyfixed therein. The second is a hard disk drive which can acceptinterchangeable and removable cartridges containing the memory media.

The removable cartridge hard disk drives have several significantadvantages over the fixed disk hard disk drives. These include theability to interchange the number of cartridges and thus provide thedisk drive with an infinitely large memory capacity. A second advantageis that any information stored on the disk or the memory media in thecartridge can, along with the cartridge, be removed and placed in asecure location should the information be of a confidential or secretnature. This can be accomplished without having to store the computer orthe disk drive itself. Additionally, large amounts of data can betransferred between computers and locations by removing the cartridgefrom one computer and transporting it to a second computer at adifferent location. Such portability of large amounts of informationstored on cartridges has become more necessary, for example, due to thedata requirement for graphic presentations.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to providing a removablecartridge disk drive which meets and significantly exceeds the industrytrend. The disk drive and removable cartridge of the present inventionprovides for a disk drive which is configured into a form factor havingabout a 2.5 inch disk or smaller and having a total disk drive height ofabout 0.75 inches (19 millimeters) or less. In this form factor, aremovable cartridge can be inserted, which removable cartridge has amemory capacity of 40 megabytes or larger. The configuration furtheraffords a reduced power consumption due to among other things, thedesign of the cartridge receiver mechanism which does not requireelectrical power for its operation. Accordingly, the present inventionprovides for the desired form factor for the newest generation ofportable, lap top, notebook, and palm top computers while affordinginfinite memory capacity. Further the removable cartridge disk drive hasthe advantage that the cartridge can be removed and locked in a securedfacility in order to protect confidential and secret informationcontained on the hard disk. Additionally, large amounts of data can betransferred from location to location as required, for example, forgraphic applications by transporting the cartridge to the desiredlocation.

It is also to be understood that while the present invention is highlyadvantageous for the above form factor, that the present invention canbe incorporated into disk drives having a disk larger than about 2.5inches and a height larger than about 0.75 inches.

It is also to be understood this the present design configuration withthe cartridge being removable provides for much higher shock immunity ata lower cost compared to systems where the entire disk drive must beremoved and stored in order to secure the data contained on the disk. Inaddition, the present invention provides for the ability to create abackup of information for each cartridge by merely copying theinformation to another cartridge.

Accordingly, the present invention provides for a disk drive which canaccept cartridges containing a disk having a diameter of greater thanand less than about 2.5 inches and preferably having a diameter of about2.5 inches to about 1.8 inches. The cartridges of the disk drive containa disk which in conjunction with the disk drive can store 40 megabytesand greater amounts of data. The disk drive includes a spindle motor forengaging and causing the disk in the cartridge to spin at theappropriate speed. Further, a mechanism is provided for movably mountingthe spindle motor to the drive housing so that the spindle motor istelescopable movable from a first position out of engagement with thedisk to a second position operably engaged with the disk. This mechanismallows the cartridge to be inserted into the drive, without the diskdrive having to physically reposition the cartridge onto a spindlemotor. Thus, without the need of a cartridge receiver mechanism forrepositioning the cartridge onto a spindle motor, the configuration ofthe present invention can be more compact, and fit within the desiredform factor which includes the drive height of about 17.5 millimetersand less.

In the present inventive configuration, the cartridge remains on thesame plane on which it is inserted into the drive. This allows thecartridge to be received in and more tightly conformed to the dimensionsof the disk drive cartridge receiver and thus affords a more accuratepositioning of the cartridge in the cartridge receiver of the diskdrive. Further, due to the fact that there is a tight fit between thecartridge and the cartridge receiver of the disk drive and due to thefact that there is a long distance between the door of the disk driveand the door of the cartridge as inserted into the disk drive,environmental contamination of the disk inside of the cartridge isgreatly diminished due to the long distance which the contamination musttravel in order to reach the disk.

Further, due to an inventive interlocking mechanism, if a cartridge isnot properly seated within the disk drive, the actuation mechanism whichpositions the heads will not be unlatched and enabled, the heads will benot be unloaded, and the spindle motor will not be enabled. The aboveinterlocking mechanism of the drive also ensures that the cartridgecannot be removed from the cartridge receiver while the spindle motor isengaging the disk, while the head is unloaded onto the disk, or whilethe head actuator mechanism and spindle motor are enabled.

The disk drive of the invention includes an ejecting mechanism, which ispart of the above interlocking mechanism, for engaging and lockinglyholding the cartridge in place in the cartridge receiver of the diskdrive and for ejecting the cartridge from the cartridge receiver. Theejecting mechanism engages another proprietary interlocking mechanism orrecess in the cartridge which is directed essentially across thedirection of insertion of the cartridge into the drive. Theseinterlocking mechanisms ensure that the cartridge is held in the driveand prevented from being withdrawn.

The drive further includes a guide rail which extends into the cartridgereceiver and mates with a guide groove in the cartridge, both of whichare disposed along the direction of insertion of the cartridge into thedrive. The tolerances of the guide rail and guide groove are tight inorder to accurately position the cartridge across the direction ofinsertion of the cartridge into the disk drive.

The cartridge receiver of the disk drive provides for guide strips foraccurately positioning the cartridge along a direction which issubstantially aligned with the height of the cartridge.

In another aspect of the invention, the disk drive includes an integralapparatus which provides for a mechanism for ensuring that the door ofthe cartridge is appropriately opened and able to accept the headactuator arm and heads. If the door is not appropriately opened, themechanism halts further introduction of the cartridge into the drive.This integral apparatus further includes a ramp mechanism upon which theactuator arm and heads can be loaded and therefrom unloaded onto thedisk. Additionally, this integral apparatus includes a mountingmechanism for mounting air filters for the disk drive.

In another aspect of the invention, the spindle motor has an inventivemagnetic clamp for seating of an armature plate of the hub of thecartridge onto the spindle motor. This magnetic clamp includes in onepreferred embodiment, a single uniform pole magnet with a single fluxpath ring. With this configuration, it is advantageous for the cartridgearmature plate to be premagnetized or otherwise acquire a magnetic polewhich is attracted by the polarity of the magnetic clamp. This magneticclamp includes, in another of the preferred embodiments, a plurality ofmagnetic rings spaced by a plurality of magnetic flux transmittingrings. Such a configuration ensures that there is an adequate magneticfield for properly seating the hub and the armature of the cartridgeonto the spindle motor while ensuring that the field is sufficientlyweak so that it will not damage any data stored on the magnetic disk ofthe cartridge.

In another aspect of the invention, a proprietary hub chuck is providedfor ensuring accurate positioning of the cartridge hub and chuckrelative to the spindle motor. The chuck includes a one piece, integralapparatus which includes datum and a spring mechanism for accuratelypositioning the chuck onto the shaft of the spindle motor. Further,there is provided an appropriate configuration on the internal surfaceof the housing of the cartridge which insures that during the process ofmating the hub and chuck to the spindle motor, that the disk does notbecome cooked in the cartridge. In a preferred embodiment, this includesa raised ring which projects on the inside of the housing towards thehub.

In further aspect of the invention, the cartridge door is removable froma closed position to an open position as a member of drive engages a camfixed to the door and urges the cam and the door to the open position.The cartridge door is configured With a spring which is imbedded intothe door in order to maximize clearance with the door open to ensurethat the actuator arms and heads can be positioned through the dooropening and unloaded onto the disk without interference between theactuator arms and heads, and the cartridge or door. The door furtherincludes a stiffener for preventing the door from bowing and for alsoretaining the spring embedded in the door, thus also ensuring that thereis appropriate clearance so that there is no interference between theactuator arms and head, and the cartridge and door as the heads areunloaded onto the disk.

In another aspect of the invention, a servo pattern embedded in theservo sector of the disk includes a servo address mark (SAM) that isdistinguishable and detectable in the presence of media defects.

A further aspect of the invention includes improved repetitive runoutcorrection for the disk drive with a removable cartridge having animbedded servo sector.

Other inventive aspects of the disk drive and removable cartridge of theinvention can be obtained from a review of the specification, claims andthe appended figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts a perspective view of an embodiment of the removablecartridge disk drive of the invention.

FIG. 2 depicts a perspective view similar to FIG. 1 with the door of thedisk drive moved to the open position.

FIG. 3 depicts a perspective view of an embodiment of the removablecartridge of the invention.

FIG. 4 depicts a perspective view similar to FIG. 3 with the door of thecartridge moved to an open position.

FIG. 5 depicts a cutaway and sectioned view of an embodiment of theremovable cartridge of the invention inserted into an embodiment of thedisk drive of the invention.

FIG. 6 depicts a cutaway and sectioned view of the disk drive of FIG. 1with the cartridge receiver removed and some of the base plate cutawayin order to depict the position of the spindle motor and the variousmechanisms, and with the door of the disk drive in an open position.

FIG. 7 is a cutaway, sectioned view similar to FIG. 6 with the door ofthe disk drive in a closed position and the various mechanismsrepositioned.

FIG. 8 depicts a cutaway and sectioned view of an embodiment of thecartridge with the cartridge hub.

FIG. 9 depicts a cross-section view of an embodiment of the spindlemotor of the disk drive of the invention.

FIG. 10 depicts a cross-sectioned and cutaway view of the hub of FIG. 8of the cartridge of the invention positioned above the spindle motor ofFIG. 9 of the invention.

FIG. 11 depicts a view similar to FIG. 10 with the hub of the cartridgeseated on the spindle motor of the invention.

FIG. 12a depicts a side view of an embodiment of an outer housing orbarrel for the spindle motor of FIGS. 4 and 10 of the invention with acam profile.

FIG. 12b depicts a view similar to FIG. 12a but with another camprofile.

FIG. 12c depicts the cam profiles of FIGS. 12a and 12b superimposed inorder to show the differences in profiles.

FIG. 13a depicts a plan view of an alternative magnetic clamp for thespindle motor of FIGS. 10 and 13b depicts a cross-sectioned view of FIG.13a at line 13b--13b.

FIG. 14 depicts another alternative embodiment of the magnetic clamp.

FIG. 15 depicts a cross-sectional view of FIG. 14 through line 15--15.

FIG. 16 depicts yet another alternative embodiment of the magneticclamp.

FIG. 17 depicts a plan broken-away view showing an embodiment of atransducer or head mounted on an actuator arm of the disk drive of theinvention resting in a position away from the disk of the cartridge ofthe invention.

FIG. 18 depicts a view similar to FIG. 17 but with the heads movedtoward the disk of the cartridge preparatory to the heads being unloadedonto the disk.

FIGS. 19a through 19e depict the indicated views of an integralapparatus for ensuring that the cartridge door is fully opened, forloading the heads onto the disk, and for mounting an air filter.

FIG. 20 depicts a side view along lines 20--20 of FIG. 17.

FIG. 21 depicts a plan view of the embodiment of the cartridge of theinvention of FIG. 23.

FIG. 22 depicts a bottom view of the cartridge of the invention of FIG.21.

FIG. 23 depicts a door end or front view of the cartridge of theinvention of FIG. 21 with the door in a closed position.

FIG. 24 depicts a partially broken-away and sectioned view of anembodiment of the cartridge door of the invention affixed to the housingof the cartridge of FIGS. 3 and 4 with the door in an open position.

FIG. 25 depicts a cross-sectioned broken-away view through line 25--25of FIG. 24.

FIG. 26 depicts a cross-sectioned view of the cartridge door of FIG. 24of the invention with the torsional spring shown in two positions.

FIG. 27 depicts the bottom view of the cartridge door of FIG. 24 of theinvention.

FIG. 28 depicts a cross-sectioned view of an embodiment of the cartridgereceiver of the disk drive of the invention with an embodiment of thecartridge of the invention inserted therein.

FIG. 29 depicts a plan view of the internal surface of a lower half ofthe cartridge housing of FIGS. 3 and 4 of the invention.

FIG. 30 depicts a plan view of the internal surface of the upper half ofthe cartridge housing of FIGS. 3 and 4 of the invention.

FIG. 31a depicts a plan view of an embodiment of the chuck for the hubof the cartridge of the invention.

FIG. 31b depicts a cross-sectioned view of FIG. 31a taken at line31b--31b.

FIG. 32 depicts a current wave form used to encode some of the servoinformation onto a servo sector on the disk of the cartridge of theinvention.

FIG. 33 depicts magnetized transitions on the servo section on selectedtracks of a disk of the cartridge of the invention formed by the currentwave form of FIG. 32.

FIGS. 34a-34b are a depiction of the waveform for a servo pattern of anembodiment of the invention.

FIG. 35a is an enlargement of the waveforms for the servo address mark(SAM) of the servo pattern.

FIG. 35b is a block diagram showing the method of detecting the SAM ofFIG. 35a.

FIG. 36 is a schematic of an embodiment for servo loop compensation andfor repetitive correction for the invention.

FIGS. 37a-37d are block diagrams for the repetitive runout correction ofthe invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the figures and in particular FIGS. 1 through 4, thedisk drive 50 and the removable cartridge 52 of the invention aredepicted. In a preferred embodiment, the housing of the disk drive 50can have a height of about 0.748 inches or 19 mm, a width across thefront of 2.76 inches and a length of about 4.0 inches. In an alternativeembodiment, the height can be 17.5 mm. The cartridge 52, in a preferredembodiment, can have a height of about 0.263 inches, a width across thefront of the cartridge of about 2.66 inches and a length of about 2.70inches. The disk contained in the cartridge is about 2.55 inches or 65 min diameter. As noted herein, other embodiments of the invention canhave other dimensions and come within the spirit and scope of theinvention.

As can be seen in FIGS. 1 and 2, the disk drive 50 includes an outerhousing 54 and a door 56 which is movable between a closed position asshown FIG. 1 and an open position as shown in FIG. 2. In the openposition, the removable cartridge 52 can be inserted through a port 58into the cartridge receiver 60. The door 56 includes a spring 62 which,in a preferred embodiment, can be comprised of an elastic form materialor other resilient material or a variety of mechanical springmechanisms, such as for example a leaf spring or a bowed spring retainedin a recess of the drive door 56, to ensure that the closing of the door56 further urges the cartridge 52 into the drive 50 in order tolockingly position the cartridge 52 as will be more fully explainedhereinbelow.

Extending from the front panel 64 of the disk drive 50 is a slide 66which is movable from the first position shown in FIG. 1 to a secondposition shown in FIG. 2. This slide 66 operates in conjunction with theinterlocking mechanisms, which will be described hereinbelow, thatensures, among other things, that unless the cartridge is properlylocked in the drive, that the spindle motor and the motor whichpositions the head relative to the disk and cartridge will not beenabled. Slide 66 also ensures, among other things, that before acartridge can be removed from the drive that the heads are removed fromthe disk and that the motors are disabled.

As can be seen in FIGS. 3 and 4, the cartridge 52 includes a cartridgedoor 68 which is movable from a closed position, shown in FIG. 3, to anopen position shown in FIG. 4. The cartridge door 68 is pivotedlymounted to the housing 70 of the removable cartridge 52 and includes amain door portion 72 and a cam or tab 74. The main door portion 72provides a closure for the port or opening 76 in the housing 70 of theremovable cartridge 52 through which the heads and actuator arm(described below) are provided in order to load the heads onto the diskcontained in the cartridge. The cam 74 extends in a direction oppositeto the main portion of the door 72 and is disposed at the beginning of adoor opening groove 78 provided in the housing 70. In a preferredembodiment, the housing 70 includes an upper half 80 and a lower half82. The door opening groove 78 is located in the upper half 80 of thecartridge housing 70.

As will be described more fully hereinbelow, the disk drive includes adoor opening projection or rail (354 in FIG. 28) which upon insertion ofthe cartridge 52 into the drive 50 comes into contact with the cam 74 ofthe door 68 causing the cam 74 to rotate from approximately zero degreesto approximately 90 degrees with the door 68 rotating from approximately180 degrees to approximately 270 degrees, both in a clockwise manner.The door opening rail then proceeds to travel along the door openinggroove 7B as the cartridge 52 becomes fully seated in the disk drive 50.

FIG. 5 depicts a cutaway view of the disk drive 50 with the top of thehousing 54 removed in order to reveal the cartridge 52 in a fully seatedpositioned. In this view, it can be seen that a recess 84 defined by thelower half 82 of the housing 54 of the cartridge 52 is received againsta stop 86 defined by the cartridge receiver 60 of the disk drive. Thestop 86 is upstanding from the base plate 92 of the cartridge receiver60. When the door 56 of the disk drive 50 is closed, the spring 62mounted on the door 56 of the disk drive 50 urges the cartridge 52against the stop 86 in order to lockingly position the cartridge 52 inthe disk drive receiver 60 in a "Y" direction or the direction ofinsertion of a cartridge into a disk drive.

As can be seen in these figures, the cartridge 52 further includes aguide groove 88 (FIG. 5) and an interlocking recess 90 (FIG. 22) whichas will be described hereinbelow, are used to accurately position andhold the cartridge in the disk drive. In a preferred embodiment, thecartridge housing and door are molded from one of the high impact anddurable plastics which are well known in the industry such as by way ofexample only, a polycarbonate plastic. The disk drive housing 54 in apreferred embodiment is comprised of a one of a number of metals (suchas aluminum) or plastics (such as polycarbonate plastic) which are knownin the industry suitable for such housings.

As can be seen in FIG. 5, the cartridge 52 is received on a base plate92 which is the floor of the cartridge receiver 60 and separates thecartridge from the various linkage mechanisms and the spindle motor(described hereinbelow). Also it is noted that the cartridge 52 istightly received within the cartridge receiver 60. It is evident fromFIG. 5 that the spaces between the sides 94, 96 of the drive housing 54and the cartridge are quite small. This being the case, and given thelength of the cartridge and the fact that the cartridge door 56 islocated, when inserted in the drive, distally from the drive doorensures that there is a substantially long, narrow path whichenvironmental contamination must follow in order to go through the door56 of the disk drive 50 and arrive at the cartridge door 68 beforepotentially contaminating the disk therein. That being the case, thepresent embodiment provides for a design with a greatly enhancedenvironmental contamination prevention scheme.

Cartridge Interlocking and Spindle Motor Telescoping Mechanisms

FIGS. 6 and 7 depict the cartridge interlocking and spindle motortelescoping mechanisms 100 of the invention. Mechanisms 100, which alongwith the rest of the drive, afford the ability of the disk drive tostore 40 megabytes or greater of information in the above specifieddesired form factor of a disk drive with about a 2.5 inch diameter diskwith a drive height of about 19 millimeters and less.

FIG. 6 depicts the mechanisms 100 which resides in the lower portion ofthe disk drive 50 below the base plate 92, which base plate 92 has beenremoved in part to better reveal the mechanisms 100. FIG. 6 depicts thedisc drive 50 with the door 56 provided in the open position and themechanisms 100 as they would be preparatory to a cartridge beingreceived in the receiver. FIG. 7 depicts the disk drive 50 with the door56 in the closed position and with the mechanisms 100 positioned in themanner that they would be positioned where a cartridge 52 received inthe disk drive 50.

The mechanisms 100 provides for the interlock functions necessary forthe insertion and removal of the cartridge into the disk drive.

It is noted mechanisms 100 allow the cartridge to be insertedsubstantially on a horizontal plane and remain in that plane while thedisk is spun by the spindle motor and the heads are loaded on the diskin order to read and write information. This design is highlyadvantageous with respect to other designs where the cartridge itselfhas to be physically lowered and set down on the spindle motor, whetherthrough mechanical linkages or mechanical linkages in combination withsolenoids. Thus, the present design affords for a more compact andreliable design for positioning the cartridge in the disk drive.

As the functions of the mechanisms 100 are performed mechanically, thepresent disk drive is highly suitable for use in a portable computer.There is no electrical power requirement and thus mechanisms 100 do notdrain the battery of the portable computer. This allows the portablecomputer to function for a longer time than would be possible were themechanism of the disk drive which afforded engagement and seating of thecartridge electrically operated. Further, should there be a powerfailure, in a solenoid system, it would be difficult to remove thecartridge and secure it. However in a mechanical system provided by thepresent invention, the cartridge can be removed at any desired time inorder to secure or transport it.

In general, one of the main features of the mechanisms 100 include thespindle motor 102 being telescopably mounted so that it can move from alower positioned as depicted in FIGS. 6 and 10 to an upper position asdepicted in FIGS. 7 and 11 in order to engage the hub 104 of thecartridge 52. Further the mechanisms 100 includes an ejector mechanism106 which has an ejector pin 108 which is used to lockingly receive andhold the cartridge 52 in the cartridge receiver 60. Ejector pin 108projects through port 109 defined in base plate 92 into the cartridgereceiver 60 in order to engage the cartridge 52. More specifically, theejector pin 108 acts in a direction which is across, and in a preferredembodiment generally perpendicular to, the direction of insertion of thecartridge into the drive, which direction of insertion is shown by thearrow 110 on the cartridge in FIG. 5.

The cartridge interlocking and spindle motor telescoping mechanisms 100perform four separate operations. These include (1) insertion of thecartridge into the drive, (2) enabling of the drive, (3) disabling ofthe drive and (4) removal of the cartridge from the drive. During theinsertion operation, certain elements (described below) are interlockedso that cartridge cannot be removed while the drive is still in use.Further the interlocking elements provide that the drive cannot beenabled if a cartridge is not inserted into the drive. With no cartridgereceived in the disk drive, the interlocking elements will not allow theheads to be loaded onto the disk or the head arm actuator motor (whichin a preferred embodiment is a voice coil motor) to be unlatched andenabled. Additionally, the spindle motor cannot be enabled without thecartridge properly inserted and seated in the cartridge receiver.

1. Insertion of Cartridge:

As the cartridge 52 is inserted into the disk drive, a cam detail orinterlocking recess 90 (FIGS. 3, 22) on the underside of the housing ofthe cartridge 52 (discussed hereinbelow in greater detail) is engaged bythe ejector pin 108 of the ejector mechanism 106. The ejector mechanism106 further includes an ejector arm 114 which pivots about pivot pin 116with an ejector arm follower pin 118 following an L-shaped cam slot 120of an index bar 122 until the ejector arm follower pin 118 is lodged inthe lower most portion of the L-shaped cam slot 120. This movementallows the spring 125 which is secured between the index bar 122 and theejector arm 114 to cause the index bar 122 to move rightwardly to theposition as shown in FIG. 7. The motion of the index bar 122 is guidedby the slots 124 and 126 which are defined by the index bar 122. Thepreviously identified fixed pivot pin 116 and the fixed pivot pin 128are disposed through slots 126 and 124, respectively and according guideand limit the motion of the index bar 122.

As the index bar 122 moves to the right from the position in FIG. 6 tothe position in FIG. 7, the follower arm assembly 130 which is pivotallymounted at pivot point 132 to index bar 122 is displaced toward theactuating arm 134. As this occurs, the follower 140 located on the endof follower arm assembly 130 remains in contact with the extended ledgeor land 142 of the actuating arm 134 as shown in FIG. 6 and spring 136which links assembly 130 to index bar 122 is stretched with the pivotpoint 132 located on index bar 122 being projected into a recess 138 ofthe actuating arm 134 as shown in FIG. 7. This action holds the indexbar 122 in the rightward position of FIG. 7. At this point, with theejector pin 108 moved to the more rearward position as shown in FIG. 7and engaging the cam detail or interlocking recess 90 of the cartridge52, the cartridge is lockingly positioned or held in the cartridgereceiver 60 and cannot be withdrawn. This process also stretches spring143 which is mounted between actuating arm 134 and ejector mechanism106. So stretched spring 143 can aid in ejecting cartridge 52. Thereverse of this process causes the cartridge to be ejected from thedrive as described hereinbelow.

The index box 122 includes an ear 137 located at an extreme leftwardposition thereon. Ear 127 along with an ear 205 of retract link 204(described below) form an interlock that prevents (1) heads fromunloading onto themselves, (2) the head actuator arm and actuator motorfrom moving and being enabled, and (3) the spindle motor from beingenabled should a cartridge not be seated into the drive so as to causeindex bar 122 to be repositioned rightwardly as ejector pin 108 isdisplaced from the position of FIG. 6 to the position of FIG. 7.

The actuating arm 134 is connected to the door 56 by a door linkage 144.As the door 56 is moved to the closed positioned as shown in FIG. 7, thedoor linkage 144 and the actuating arm 134 move rearwardly as guided byslots 146 and 148 which slots are constrained by fix pins 150 and 152provided through slots 146, 148. During the first half of the motion ofthe actuating arm 134, the ejector mechanism 106 is armed for ejectionof the cartridge 52 from the disk drive 50. This is accomplished due tothe displacement of the follower 140 rightwardly into the now movedrecess 138 of the actuating arm 134 shown in FIG. 7 with theaccompanying contraction of spring 136 which is connected between an endof the follower arm assembly 130 and the index bar 122. Thus, follower140 is now placed in the path of ramp 139 of recess 138. For ejection,ramp 139 urges follower 140 and thus index bar 122 leftwardly (asactuating arm 134 is pulled forwardly, by the drive door opening) to theposition of FIG. 6, freeing pin 118 from the bottom of the L-shaped camslot 118 and allowing spring 125 to rotate ejector pin 108 clockwise inorder to eject the cartridge.

During the second half of the motion of the actuating arm 134 in arearwardly direction, a follower roller 154 on the spindle motoractuating arm 156 follows the slot cam detail 158 on the actuating arm134 causing the motor actuating arm 156 to rotate in a counterclockwisedirection. As this occurs, the spindle motor actuating arm 156 pivotsabout fixed pivot pin 160. Fixed pivot pin 160 is disposed in the slotcam detail 158 of the actuating arm 134 in order to assist in directingthe actuating arm 134 in a rearwardly direction.

As the spindle motor actuating arm 156 rotates, it pulls the motor draglink 162 to a rightward position as shown in FIG. 7. The motor drag link162 is attached to the outer rotating barrel 164 of the motor lifting ortelescoping mechanism 168 (more fully described hereinbelow). Thespindle motor 102 is accordingly raised into contact with the cartridgeand base plate 92 as the rotating barrel 164 is rotated in acounterclockwise direction from the position of FIG. 6 to the positionof FIG. 7. The rotation of the outer rotating barrel 164 is guided byfixed pins 170 which are disposed within curved slots 172 which aredefined by the outer rotating barrel 164. As rotation of barrel 164occurs, the follower pin 174 affixed to the motor drag link 162 moves inthe slit 176 defined in the spindle motor actuating arm 156. A spring178 is connected between the motor drag link 162 and the spindle motoractuating arm 156 in order to encourage the motion of the follower 174in the slit 176 thus ensuring the appropriate freedom of motion betweenthe motor drag link 162 and the spindle motor actuating arm 156.

At this point, the spindle motor 102 has been telescoped upwardly intocontact with the hub 104 of the cartridge 52 and also the bottom of baseplate 92.

2. Enabling the Drive:

The disk drive 50 is now enabled by moving the slide 66 rightwardly fromthe position of FIG. 6 to the position of FIG. 7. The slide 66 isconnected to an interlock bar 180 which slides across the path of theactuating arm 134 when and only when the actuating arm 134 is fullydisposed in a rearward position as shown in FIG. 7. Thus, it can beappreciated that with the disk drive door 56 open, that the slide 66cannot be moved fully rightwardly as the interlock bar 180 would comeinto contact with the actuating arm 134 and thus the drive cannot beenabled.

A detent arm assembly 182 held by a spring 184 provides positivelocation of the interlock bar 180 in the first position shown in FIG. 6and the second position shown in FIG. 7. The motion of the interlink bar180 is guided by the slots 186, 187 defined by the interlock bar 180 andby the fixed pins 188, 189 which are disposed in slots 186, 187. Asinterlock bar 180 moves between the first and second positions as shownin FIGS. 6 and 7, the roller follower 190, located on the detent armassembly 182, moves between the first and second recesses 192, 194 onthe interlock bar 180. With the assistance of the spring 184 theinterlocking bar 180 causing the detent arm assembly 182 to pivot aboutthe fixed pin 189, resulting in the interlock bar 180 being retained ineither the position of FIG. 6 or FIG. 7.

Connected to the interlock bar 180 is a linkage assembly 196 whichcomprises a retract actuating arm 198. Arm 198 is pivoted about fixpivot pin 200 in a counterclockwise direction as the retract actuatingarm 198 is directly connected to the interlock bar 180 by the pin andslot arrangement 202. The linkage assembly 196 further includes aretract link 204 which is pivotally pinned to the retract actuating arm198. Retreat link 204 includes ear 205 which can interlock with ear 127of index bar 122 to prevent operation of the drive should a cartridgenot be properly inserted in the cartridge receiver 60. FIG. 6 shows howears 127 and 204 interfere and prevent enablement of the drive andunloading of the heads onto themselves if a cartridge has not bereceived in cartridge receiver 60. FIG. 7 shows ear 127 moved out of theway of ear 205 as the cartridge has been properly inserted in thecartridge receiver 60, so as to move ejection pin 108 and thus causingthe index bar 122 to move rightwardly. This action allows slide 66 toenable the disk drive motor and allows the heads to be unloaded onto thedisk.

The retract link 204 is also pivotally connected to the retract arm 206by pin 208. The retract arm 206 is pivotedly mounted about fix pivot pin210. The retract arm 206 moves in a clockwise direction from theposition in FIG. 6 to the position of FIG. 7 during the motion of theinterlock bar 180 to the rightward position as shown in FIG. 7. Thismotion of the retract arm 206 takes it out of the path of the motion ofthe head actuator assembly and in particularly pin 283 of the actuatorarm 282 (described below) and thus allows the heads under the control ofa voice coil motor to be unloaded onto the disk. Motion of the slide 66leftwardly to the position of FIG. 6 causes the retract arm 206 to movein a counterclockwise direction causing the heads to be removed from thedisk and parked as described below, preparatory to the removable of thecartridge 52 from the drive 50. It is noted that portion 93 of baseplate 92 onto which the voice coil motor and head actuator arm (FIG. 20)are mounted is lower than the rest of the base plate 92 and that theelongate end 207 projects through a port in base plate 92 and over thelower portion 93 in order to engage pin 283 (FIG. 20) of the actuatorarm 282 and thus to remove and hold the head actuator arm 282 with thehead parked off the disk.

The retract arm 206 includes a retract follower pin 212 which moves thedown the curved camming surface 214 of the switch lever 216. The retractfollower pin 212 is maintained in contact with the curved cammingsurface 214 by the spring 218 which is connected between the retract arm206 and the switch lever 216. During the last portion of the motion ofthe retract follower pin 212, pin 212 drops off shoulder 220 of thecurved camming surfaces 214 such that the switch lever 216 rotates in aclockwise direction about fixed pivot pin 124. The switch lever 216rotates due to the contraction of spring 218. This clockwise rotation ofthe switch lever 216 depresses a switch arm of switch 222.

With the above arrangement, the disk drive 50 is not enabled if acartridge 52 has not been inserted into the cartridge receiver 60. Withno cartridge 52 in the cartridge receiver 60, the ejector arm 114 willnot have been rotated in a counterclockwise manner from the position ofFIG. 6 to the position of FIG. 7 and the index bar 122 would not havebeen moved to the right as shown in FIG. 7. With the index bar 122 inthe position of FIG. 6, the ear 127, which is located on the index bar122, blocks ear 205 on retract link 204 and thus blocks the rotation ofthe switch lever 216 during the rotation of the switch lever 216 in aclockwise manner and the switch 222 is not turned on and the motors anddrive are not enabled. Further, end 207 cannot move sufficiently toallow the actuator arm to unload the heads onto themselves, there beingno cartridge received in the drive.

All of the above described linkages and arms are positioned about thetelescoping spindle motor 102 and are substantially tangential to thespindle motor. It is this configuration which also affords the presentdrive 50 the ability to perform all of the interlocking and safetyfunctions while compactly configuring the disk drive 50 into therequired form factor as specified about.

It is noted that in a preferred embodiment, that the various linkagesare comprised of steel, with the rotating barrel being brass.

3. Disabling Drive:

The drive is disabled by moving the slide 66 to the leftward position asshown in FIG. 6. When this occurs, the above linkages and assembliesmove directly opposite to that described above in order to move theswitch lever 216 away from engagement with the switch 222 thus disablingthe drive.

4. Removable of the Cartridge:

After the slide 66 is moved leftwardly to the position of FIG. 6, thedoor 56 can be opened as the interlock bar 180 is moved out of the wayof the actuating arm 134, allowing the actuating arm 134 to movefrontwardly toward the door as the door is opened. During the first halfof the movement of the actuating arm 134 and thus the first half of themotion of door rotating to an open position, the motor is disengagedfrom the hub. This occurs as outer rotating barrel 164 is moved in aclockwise direction from the position of FIG. 7 to the position of FIG.6 through the movement of the motor lifting or telescoping mechanism 168which includes the spindle motor actuating arm 156 and the motor draglink 162. As this occurs, the spindle motor 102 is telescoped downwardlyout of contact with the hub of the cartridge (as will be more fullydescribed hereinbelow). During the second half of rotation of the doorto the fully opened position, the cartridge is ejected from the drivedue to the motion of the ejector pin 108 from the position of FIG. 7 tothe position of FIG. 6 under the influence of the above describedlinkages and springs associated with the motion of the ejector pin 108.Essentially, as the actuating arm 134 moves forwardly towards the door56, the follower 140 rides up on the cam surface 139 of the recess 138until it reaches the extending ledge or land 142. This action urgesfollower arm assembly 130 against stop 123 of index bar 122, which urgesthe index bar 122 leftwardly allowing the spring 125 to rotate theejector mechanism 106 in a clockwise direction ejecting the cartridge,as the ejector arm follower pin 118 is caused to follow the L-shaped camslot 120 back to the original position as shown in FIG. 6.

Hub Telescoping Mechanism

FIGS. 8 and 9 depict the cartridge 52 and the spindle motor 102 of thedisk drive 50. In particular in FIG. 8, the hub 104 of the cartridge isshown in cross-section with the rest of the cartridge 52 cutaway. FIGS.10, 11 and 12 depict the spindle motor telescoping mechanism 168 whichenables the spindle motor 102 to engage the hub 104. As can be seen inFIG. 10, the spindle motor is out of engagement with the hub 104. InFIG. 11, the spindle motor 102 has been telescoped into engagement withthe hub 104.

Prior art designs for removable cartridge disk drives require that thecartridge be inserted into a cartridge receiver and that the cartridgereceiver be then repositioned using various linkages and/or solenoidscausing the cartridge hub to be seated generally downwardly onto theshaft or spindle of the spindle motor. Such an arrangement requires alarger form factor than is desirable and provided by the presentinvention. In the present invention, the cartridge 52 is received andmaintained in the cartridge receiver 60 in a single plane, and remainsin that single plane until the cartridge is again ejected from the diskdrive 50. This being the case, the spindle motor must move andpreferably telescope from a lower position to an upper position intoengagement with the hub 104 of the cartridge 52. As will be describedmore fully below, the spindle motor 102 is free to move only axiallyfrom the lower position to the upper position into engagement with thehub 104. The spindle motor 102, as will be explained hereinbelow, isrestrained from rotating in a clockwise or in a counterclockwisedirection about the telescoping direction thereby eliminating the stresson any motor flexible cabling. In a preferred embodiment, spindle motor102 moves substantially perpendicularly to the base plate 92 of thedrive which base plate 92 forms the bottom of the cartridge receiver 60upon which the cartridge is received (FIGS. 10 and 11).

Accordingly, this present design eliminates the need for a cartridgereceiver which must move and set the cartridge down on the spindle motorand thereby affords the advantage of a removable cartridge disk drivewhich has a thinner form factor.

After the cartridge 52 is inserted into the cartridge receiver 60, theactuating arm 134 through the use of the spindle motor actuating arm 156and the motor drag link 162 causes the outer rotating barrel 164 torotate in a counterclockwise direction. The outer barrel has threeidentical cam profiles, such as profile 228 (FIG. 12), which engagethree pins, such as pins 230, which extend from the spindle motor 102.An inner stationary barrel 232 has slots 234 in which the pins 230 aredisposed. These slots 234 are in the preferred embodiment substantiallyperpendicular to the drive base plate 92 and prevent rotation of thespindle motor 102 as the motor is telescoped upwardly towards the baseplate 92 with the pins 230 following the cam detail 228. To accomplishthis, the inner stationary barrel 230 is rigidedly pinned to the baseplate 92 while the outer rotating barrel 164 rotates relative thereto asdescribed hereinabove. Accordingly, the motor is telescoped untilshoulder 236 of the spindle motor 102 seats against the bottom of baseplate 92. As this occurs, with the cartridge inserted in the cartridgereceiver, the motor shaft 252 engages the hub chuck 238 (FIGS. 10, 11,31a) of the cartridge. The magnetic clamp 240 on the spindle motor rotor242 seats the armature plate 244, the hub chuck 238 and the hub 104 ofthe cartridge onto the spindle motor 102 by magnetically drawing thearmature plate 244 into contact with the magnetic clamp 240. It is to beunderstood that the magnetic clamp 240 engages the armature plate 244,in a preferred embodiment, before the spindle motor 102 has been fullyseated against the drive base plate 92. The spindle motor 102 is finallyand fully seated against the drive base plate 92 with the movement ofthe motor drag link 162 and the spindle motor actuating arm 156 whichcontinues to cause the outer rotating barrel 164 to rotate. The spring178 secured between the motor drag link 162 and the spindle motoractuating arm 156 transmits force through the rotating barrel 164 sothat the spindle motor 102 is positively loaded against the drive baseplate 92 as shown in FIG. 11.

An alternative embodiment for the outer rotating barrel 164 is shown inFIG. 12b. The outer rotating barrel 165 in FIG. 12b includes two camdetails, such as cam detail 229 depicted and one cam detail 228 oralternatively three cam details such as cam detail 229.

As indicated, the spindle motor 102 has a down position (cartridge diskdisengaged) and an up position (cartridge disk engaged). To assure thatthe motor is firmly pushed up against three pads on the underside of thebase plate 92, at least two cam details 229 are used. Cam detail 229includes an integral beam springs 231 with a cam surface 233 that ishigher than that of the cam detail 228.

When the motor 102 is guided up the fixed cam detail 228 with one pin230, the two other pins 230 deflect the beam springs 231 in a downwarddirection, which results in a upward force on the two pins 230 forcingthe motor 102 upwards against the pads on the base plate 92.

FIG. 12b show beam spring 231 with the cam surface 233 in an undeflectedposition and an outline of pin 230 where it would be positioned if itwere disposed in cam detail 229. As seen, pin 230 would have displacedbeam spring 231 downwardly. FIG. 12c shows cam surface 233 of beamspring 231 deflected downwardly, and superimposed thereover the camdetail 228 with pin 230 disposed therein. It is noted that cam surface233 pushes pin 230 against the upper surface of cam detail 228 but thatthe upper surface of cam detail 229 does not contact or limit the motionof pin 230.

The above arrangement ensures that the spindle motor 102 makes contactwith the three pads on base plate 102 resulting in accurate seating ofthe motor 102 and no system vibration that could result if motor 102were not so seated.

Disk Drive Spindle Motor and Clamp Magnet

In a preferred embodiment, the spindle motor 102 is of the brushless DCspindle motor variety with the above identified clamp magnet 240. Thespindle motor 102, in a preferred embodiment, is also of the radial gap,outer rotor configuration and includes the rotor 242 as well as thestator 246 (FIG. 9). The stator 246 includes the stator windings andlamination 248 and mounts the bearings 250 upon which the spindle shaft252 and the rotor 240 rotates. The rotor 242 includes, in a preferredembodiment, permanent magnets 254 which cause the rotor 242 to rotateunder the influence of the stator windings 248.

In FIG. 9, the combination of the clamp magnet 240 located on the backof the rotor 242 in a magnetic removable cartridge disk drive is a novelconfiguration. The clamp magnet 240 includes a single uniform polemagnetic ring 241 with a low reluctance magnetic flux path ring 243positioned outboard thereof. The flux path ring 243 projects above themagnetic ring 241 and can contact the armature plate 244.

With the embodiment of FIG. 9, it is to be understood that greatadvantages can be obtained from the production of all of the clampmagnets 240 for all of the disk drives 50 having a single uniform polemagnetic ring 241 which always has the same polarity as seen from acartridge 52 inserted into the disk drive. By way of example, themagnetic ring 241 could have a north pole facing away from the spindlemotor toward the cartridge. The armature plate 244 could then either bepremagnetized with a south pole extending away from the cartridge 52,and thus seen by the clamp magnet 240, or could be left unmagnetized. Inthe first arrangement, the south pole of the armature plate 244 would beattracted by the north pole of the clamp magnet 240. In the secondarrangement, after several insertions of the cartridge into the drive,the armature plate 240 would acquire a south pole orientation extendingin a direction away from the cartridge and thus be attracted by thenorth pole of the spindle motor. Alternatively, it is to be understoodthat the clamp magnets 240 can have a south pole directed away from thespindle motor and the armature plate 244 can have a north pole directedaway the removable cartridge 52.

Such arrangements are highly advantageous as the flux lines in thearmature plate take a preferred direction with respect to the flux linesin the clamp magnet and thus there is an increase in clamping forcebetween the armature plate and the clamp magnet. Were the same polesoutwardly projecting from both the clamp magnet and the armature plate,the clamping force between the two would be decreased. This might occurif some of the clamp magnets for the spindle motors were manufacturedwith a north pole facing up and some were manufactured with a south polefacing up. Thus, it is advantageous to have all of the clamp magnets,for all of the spindle motors for all of the disk drives manufacturedwith the same polarity facing up.

Alternative embodiments of the below discussed clamp magnet 240 have anovel design for magnetically drawing thereto and holding the armatureplate 244 of the cartridge 52. The novel design meets two goals. First,the clamp magnets have been designed to have a sufficiently high forcein order to draw and hold the armature plate thereto under shockloading, while secondly having a sufficiently weak leakage field thatany data on the magnetic disk is not affected by or exposed to theleakage field from the clamp magnet as the disk is inserted over theclamp magnet. Thus, the clamp magnet must be designed to have sufficientforce to hold the disk in place under shock loading and have asufficiently weak field to obviate erasure of the data. Greater forcerequires a greater magnetic field. Hence the design of the clamp magnetprovides for sufficient high force with a sufficiently weak leakagefield.

FIGS. 13a, 13b depict a first alternative embodiment of the clamp magnetof the invention. In this embodiment, a clamp magnet 245 is comprised ofthree rings 258 which are comprised of a low reluctance magnetic fluxmaterial such as for example steel as well as three magnet rings 260. Ascan be seen in FIG. 13a, 13b the rings 258 and magnet rings 260 areinterposed with each other with the outer most being the low reluctancemagnetic flux path ring 258 followed alternatively by a magnet ring 260and then a ring 258 and progressing inwardly towards the spindle shaft252. In this configuration, the low reluctance magnetic flux path rings258 extend further away from the rotor 242 than do the magnet rings 260.It is noted that the distance over the top of any of the magnets 260between two steel rings 258 is relatively short. This decreased distancereduces the flux leakage which would normally occur in a magnetic clampwhere there is only one magnet which essentially occupies the radiallength of the three magnet rings 260 and the three steel rings 258.Further, as the three rings 258 come into contact with the armatureplate 244, this contact provides a low reluctance flux path for themagnetic flux and permits the required binding force to be asserted uponthe armature plate.

In a preferred embodiment, the magnetic rings 260 are comprised of HB061material and the steel rings 258 are comprised ST461 material. Thearmature plate 244 in a preferred embodiment is comprised of magneticstainless steel. With the configuration as shown in FIGS. 13a, 13b, themagnetic force on the armature plate is minus 10.7N (Newtons). Theleakage level is 184× 10 ⁻⁵ T (Tesla) at 4 mm.

In a similar configuration, with only two steel rings 258 and twomagnetic rings 260 made of the same materials, the force on the armatureplate is equal to a minus 8.5N with the leakage level being 20 G (2 mT)of 4 mm. In such a configuration the leakage is satisfactory but theforce is to low for the present embodiment.

FIGS. 14 and 15 depict an alternative embodiment of the clamp magnet ofthe invention which clamp magnet is identified by the numeral 262. Thisclamp magnet is made of the same material of the prior clamp magnet butis less expensive to manufacture. This clamp magnet has the sameproperties of the prior clamp magnet of FIGS. 13a, 13b. In thisembodiment, the magnetic element 264 is configured much like a gear withan inner ring 268 with a plurality of spaced radial projections 270extending therefrom. The low reluctance magnetic flux path element 272which is comprised of steel, in a preferred embodiment, is configured asan inwardly directed gear with an outer ring 274 with spaced radialprojections 276 which are inwardly directed. It is noted that the spacedradial projections 270 of the magnetic element 264 alternate with thespaced radial projections 276 of the low reluctance flux path element272. Such an arrangement gives a force and flux leakage which arecomparable to the embodiment of FIGS. 13a and 13b. In an alternativeembodiment for FIG. 14, the positions of the flux path element 272 andthe magnetic element 264 can be switched.

FIG. 16 depicts yet another embodiment of a clamp magnet 278 of theinvention. This clamp magnet 278 includes, in a preferred embodiment,eighteen individual magnetic poles 279 which alternate between north andsouth poles. The division of the magnetic clamp 278 into a plurality ofalternating poles reduces the leakage flux, but has the desired magneticforce in order to pull down the armature plate of the cartridge. In suchan arrangement, each of the poles is afforded about 20 degrees with thechuck force predicted to be about minus 5N and the leakage less than 3mT at 4 mm distance.

Integral Head Loading Ramp, Air Filter and Removable Cartridge DoorSafety Stop

FIGS. 17, 18, 19 and 20 depict another aspect of the invention whichincludes an integral element 280 which performs among other things thefunctions of providing for dynamic head loading and unloading, housing arecirculating air filter, and providing for a cartridge door safetystop. Additionally through the proper selection of materials, theintegral element can provide for an electro-static discharge drain forthe cartridge. FIG. 19 depicts the integral element 280 by itself whileFIGS. 17 and 18 depict the integral element 280 in conjunction with thedisk 256 from the cartridge 52 as well as the actuator arm 282 uponwhich is mounted the head-gimble assembly 284 which includes themagnetic head or transducer 286. The actuator arm 282 is moved in aclockwise and a counterclockwise direction by the actuator motor 290which in a preferred embodiment is a voice coil motor. As can be seen inthe figures, outboard of the head-gimble assemble 284 is an extension292 of the actuator arm 282 which rides on a ramp provided by theintegral element 280 as will be described more fully hereinbelow.

FIG. 17 shows the extension 292 of the actuator arm 282 parked on theramp of the integral element 280. FIG. 18 depicts the extension 292 ofthe actuator arm 282 positioned just before the transducer 286 would beunloaded onto the disk 256.

The integral element 280 which, in a preferred embodiment, is cast as aone-piece, integral, element, includes a base 294 which serves as aholder for an air filter element 296 which can be inserted therein. Thebase 294 as can be seen in FIG. 19d includes two rectangular shapedopenings 298 which are placed side-by-side and allow air to flow throughair filter elements 296. Extending from the base 294 is a projection300. Projection 300 in a preferred embodiment is substantiallyperpendicular to the base 294. Projection 300 is bifurcated into acartridge door safety stop 302 and a head ramp 304. The cartridge safetystop 302 (side profile of FIG. 19b) includes a projected end 306 whichis substantially flat and perpendicular to the plane of the disk 256.Further as the integral element 280 is secured to the base plate 92 ofthe disk drive upon which the cartridge is received, the projected end306 is perpendicular to the base plate 92. Extending rearwardly andupwardly from projected end 306 is a cartridge door ramping surface 308.

Additionally, the cartridge door safety stop 302 is disposed in adirection which is parallel to the direction of insertion of thecartridge into the drive and that it extends into the cartridge that isproperly seated in the cartridge receiver.

As the cartridge is inserted into the disk drive and in particular intothe cartridge receiver 60, the cartridge door 68 (as will be more fullyexplained hereinbelow) is caused to rotate by the cartridge receiver inorder to allow the actuator arm 282 to transport the head-gimbleassembly 284 to a position where it can be loaded onto the disk 256. Thecartridge door 68 is opened by rotating it from zero degrees toapproximately ninety degrees. Due to assembly and part tolerances, thecartridge door 68 may not reach a full ninety degrees of rotation. Thisbeing the case, there might not be enough clearance for allowing thehead- e gimble assembly 284 to be inserted into the cartridge.Accordingly, the cartridge door safety stop 302 provides for theprojected end 306 which will stop the further insertion of the cartridgeinto the drive if the door has not reached at least approximately aminimum of 80% of the required rotation from zero to ninety degrees.Further, if the cartridge door has reached a minimum of 80% of its fullrotation, the cartridge ramp surface 308 will ensure that the doorrotates 100% to a position of ninety degrees relative to its closedposition, thus ensuring that there will be no interference between thedoor and the unloading of the head onto the disk.

The head ramp 304, as can be seen in the figures and in particular FIG.19f includes a bifurcated end 310 which includes an upper ramp surface312 and a lower ramp surface 314. As can be seen in FIGS. 17 and 18,with the cartridge inserted into the drive, the disk 256 is disposedbetween the upper and lower ramp surfaces 312, 314. The actuator arm 282under control of the actuator motor 290 can then move the head-gimbleassembly 284 from a parked position as shown in FIG. 17 to a positionshown in FIG. 18 where the heads are at the end of the ramps 312, 314,preparatory to being immediately unloaded onto the disk 256. As can beseen from the figures, the extension 292 of the actuator arm 282 ridesup on the upper ramp surface 312. A similar extension rides on the lowerramp surface 314 in order ramp the lower head away from the lowersurface of the disk 256. In a preferred embodiment it can be seen thatthe bifurcated end 310 is directed so that it is substantiallyperpendicular to the actuator arm 282 and substantially along a radiusof the disk 256.

The recirculating air filter element 296 as previously indicated, issecured to the base 294. The air filter element 296 is provided in asemi-circular configuration and is made out of materials which are knownin the trade. In operation, a positive pressure field is maintained onthe front or convex side of the air filter element 296, while a negativepressure field is maintained on the back or concave side of the element296. The total difference between the positive and negative pressure isproportional to the relative flow of air through the air filter.

The integral element 280 additionally includes an air flow diverter 316which extends from the base 294 at a location distal from where theprojection 300 extends. The projection 300 extends from a position whichis one end of the air filter 296 while the air flow diverter 316projects from a position which is on the other side of the air filter296. The diverter 316 is substantially a flat plane which projectsoutwardly in the plane of the disk 256 and has a curved edge 318 whichsubstantially conforms to the portion of the disk 256 that is locatedadjacent thereto as shown in FIGS. 17 and 18. The air flow diverter 316is used to maximize the pressure differential across the air filterelement 296. With the disk 256 rotating in a preferred embodiment in acounterclockwise direction, the air flow diverter 316 assists there-directing of the air rotating with the disk into the cavity whichexists in front of the air filter elements 296 (convex side) in order tocreate a higher positive pressure.

Integral element 280 can have affixed thereto a stop mechanism 320 whichin a preferred embodiment is comprised of an elastomer or other energyabsorbing material or mechanism. The stop mechanism 320 is used to dampand stop uncontrolled rotary motion of the actuator arm 282 and thus thehead-gimble assembly 284 and decelerate that motion should the actuatormotor 290 attempt to park the heads on the bifurcated end 310 at toorapid a velocity.

Accordingly, the stop mechanism 320 prevents rapid deceleration of theactuator arm 282 and thus mechanical damage to the actuator arm 282 andthe head-gimble assembly 284. The elastomer may be in a preferredembodiment, attached to the integral element 280 by a liquid or pasteadhesive or pressure sensitive adhesive tape. Alternatively, theelastomer can be mechanically interlocked to the integral element 280 asthe integral element 280 is itself being molded. In a preferredembodiment, the elastomer is a thermal plastic elastomer and it can bemolded into a liquid crystal polymer plastic which comprises theintegral element 280.

The integral element 280 further includes the function of providing foran electro-static discharge drain for the cartridge and drive to protectboth the magnetic heads 286 and the disk 256 from damage. This functionis performed by the specific material chosen for the integral element280. Should the material be of conductive, metallic material, thisfunction is automatically performed. However, in a preferred embodiment,the integral element 280 will be comprised of the above liquid crystalpolymer plastic to which will be added a substantial volume, by percent,of a conductive fiber. The amount of conductive fiber, in a preferredembodiment, shall reduce the natural non-conductivity of the polymer toa surface conductivity of less than 5000 ohms. In such an arrangement,the integral element 280 will be able to discharge electrostatic chargebuilt up on the heads and the disk.

It is noted that prior disk drives include similar types of rampfunctions and recirculating air filter functions. However, none providethe integral element 280 which affords a compact design allowing theinventive disk drive 50 and removable cartridge 52 to fit within theform factor above specified. Additionally, the present design providesfor a lower manufacturing costs.

Cartridge Receiver Mechanism

The present disk drive 50 includes a cartridge receiver 60 which canaccurately position the cartridge 52 with respect to the disk drive 50.

It is to be understood that in prior art disk drives, which haveremovable oartridges, that the cartridge receiver is generally guidedalong its edges and lowers a cartridge to a rigidly mounted spindlemotor. This configuration, while working well, requires large clearancesbetween the inside of the cartridge receiver and the cartridge toprevent wedging due to a drawer effect (unfavorable length-to-widthratio). The present invention does not require the movement of thecartridge receiver (as in the present design, the spindle motortelescopes into contact with the cartridge) and thus clearances can betighter with the overall form factor of the drive being smaller andpreferably, as specified above. The design of the disk drive 50 has afavorable length-to-width ratio and is not susceptible to wedging due tothe drawer effect.

Further, due to the small size of the form factor for this removablecartridge disk drive 50, the clearance allowed between the hub 104 ofthe cartridge 52 and the inside of the cartridge 52 are very small.Thus, very accurate positioning of the cartridge in the drive and thedisk in the cartridge is required in order to prevent the rubbing of thedisk which is mounted on the hub against the inside of the cartridgeduring operation. The present embodiment provides for accuratepositioning as well as smooth insertion and ejection of the cartridgerelative to the drive with low friction forces and without the danger ofwedging.

These advantages are carried out in the present embodiment whichprovides for a guide rail 88 used in conjunction with a guide groove332, and a fixed stop 86 (FIG. 5) along with a recess 84 in thecartridge, as well as a spring 62 mounted in the disk drive door 56. Inaddition guide strips 336, 338, 340 and 342 are provide for ensuringaccurate cartridge positioning. In the present design, the manufacturingtolerances are advantageously smaller across the small width of theguide rail 88 and the guide groove 332 than over the total width of thecartridge and the inside of the cartridge receiver.

The above embodiment of the present invention is preferably implementedas follows. The guide rail 88 extends from the cartridge receiver 60into the cavity 344 which receives the removable cartridge 52. The guiderail 88 is accurately machined and is received in a precisely moldedguide groove 332 which is provided in the upper half 80 of the cartridgehousing 70 (FIG. 28). The guide rail 88 and the guide groove 332 aredisposed in a direction which is parallel to the direction of insertionof the cartridge into the drive. Using the convention shown in FIG. 5,the guide rail and guide groove are disposed in the "Y" direction. Thus,when the cartridge is inserted, the guide rail 88 and guide groove 332accurately position the cartridge relative to the "X" direction or thedirection which is perpendicular to or across the direction of insertionof the cartridge into the drive.

Although the guide rail 88 as shown has been provided in the cartridgereceiver and the guide groove 332 as shown has been provided in thecartridge that equivalently the guide rail could be extending fromcartridge with the guide groove provided in the cartridge receiver ofthe drive. This alternative embodiment would result in the same functionof accurate positioning of the cartridge in the cartridge receiver in adirection which is perpendicular to or across the direction of insertionof the cartridge into the drive.

Additionally, for accurately positioning the cartridge in the drive inthe "Z" direction or the direction of the height of the cartridge,between its upper and lower substantially parallel surfaces 350 and 352,guide strips 336, 338, 340 and 342 are provided extending into thecavity 344 from the cartridge receiver 60. As can be seen in FIG. 28,guide strip 336 is comprised of two longitudinal elements, one on eachside of the guide rail 88. These guide strips 336 are provided along thedirection of insertion of the cartridge into the drive and substantiallyparallel to the guide rail 88. Additionally, guide strip 338 iscomprised of two longitudinal elements which again are extending fromthe cartridge receiver into the cavity and are substantially parallel tothe direction of insertion of the cartridge into the cartridge receiver.

The guide strips 340 and 342 extend from the bottom of the cartridgereceiver 60 and again are longitudinal in the direction of insertion ofthe cartridge into the drive. At the mouth of the cartridge receiver theguide rails and guide strips are slightly beveled to ease the insertionof the cartridge into the drive.

At the end of the insertion stroke of the cartridge into the cartridgereceiver that is a rigid stop 86 (FIG. 5). The rigid stop 86 isupstanding from the base plate 92. This rigid stop 86 mates with agroove or recess 84 defined in the cartridge. As the door 56 of the diskdrive is closed, spring 62 mounted thereon is urged against thecartridge to in turn urge the cartridge firmly against the stop 86 inorder to accurately position the cartridge in the "Y" direction or inthe direction of insertion of the cartridge into the drive.

Finally, as seen in FIG. 28 located between the elements of guide strip338, is a door opening rail 354 which is loosely received in a groove 78of the cartridge. As is more fully described elsewhere, as the cartridgeis inserted into the drive, the door opening rail 354 trips or causesthe cam or tab 74 of the cartridge door 68 to rotate clockwise as thedoor opening rail 354 is received into the door opening groove 78 inorder to open the cartridge door 68 preparatory to the heads beingactuated into the cartridge through the cartridge door and unloaded ontothe disk.

As can be seen in FIG. 28, the clearances on all sides of the cartridgerelative to all sides of the cartridge receiver are relatively small.Also due to the fact that the door of cartridge when opened ispositioned at the rearward end of the cartridge receiver, distallylocated from the door 56 of the disk drive 50, that contamination fromenvironmental sources is greatly reduced. This is due to the fact thatthe paths from the door 56 of the disk drive 50 to the door 68 of thecartridge 52 are quite long and narrow thereby providing a significantbarrier to the infiltration of environmental contaminates into theinside of the cartridge.

Removable Cartridge With Imbedded Interlocking Mechanism

As can be seen in FIG. 22, in the lower half 82 of the cartridge housing70 and more particularly disposed in the lower surface 352 is aninterlocking recess 90. Interlocking recess 90 along with recess 84 areopened to the front face 98 of the cartridge 52 which front face 98additionally mounts the cartridge door 68. It is in the interlockingrecess 90 that the cartridge engaging ejector pin 108 is received inorder to lockingly position the cartridge into the disk drive. As can beseen in FIG. 22, the interlocking recess 90 is essentially a groovewhich extends in a direction which is perpendicular to or across thedirection of insertion of the cartridge into the drive. In particular,the interlocking recess 90 includes an opening 360 which communicateswith the front face 98. Extending from the opening 360 is a ramp surface362. Extending from the ramp surface 362 is a flat surface 364 which isalso directed substantially perpendicular to or across the direction ofinsertion of the cartridge into the drive. The ramp surface ends in asemi-circular cavity or stop 366 which is positioned somewhat sidewardlyfrom the opening 360 in a direction which is perpendicular to or acrossthe direction of insertion of the cartridge into the drive. With thecartridge inserted into the drive, the ejection pin 108 comes to a finalresting position in the stop 366 after having entered the opening 360and travelled along the ramp surface 362. Thus, the ejector mechanism106 is urged from the uncocked position of FIG. 6 to the cocked positionof FIG. 7, with the pin 108 received in the semi-circular stop 336, thecartridge is locked into the drive and prevented from being withdrawn.It is additionally noted that in this embodiment depicted, theinterlocking recess 90 is located below the guide groove 88 which islocated on and incorporated into the upper surface 350 of the upper half80 of the cartridge. The advantages of having these two features closelyspaced are found in improved dimensional accuracy and a lesser effectfrom thermal expansion. Other relationships between these two featuresare possible and come within the spirit of the invention.

Removable Cartridge With Hub Chuck

In order to satisfy the present form factor requirement, the hub chuck238 of the present embodiment is preferably of a one-piece construction,having two integrally formed springs and two datum surfaces. Thisarrangement allows for a very thin cartridge configuration and a drivewith very low height and small spindle motor shaft. Further, the chuck238 can be inexpensively made.

In a preferred embodiment, the hub chuck 238 is formed from a singlepiece of material which can include, for example, phosphorous bronze.The chuck is circular and has stamped therein a central bore 378 and alip 380 upstanding therefrom. Formed on the central bore and lip aredatum 382 and datum 384. Datum 382 and 384 are provided with lead-inchamfers which assists in the seating of the hub chuck 238 onto thespindle shaft of the spindle motor. In a preferred embodiment, thesedatum can be chromed or otherwise plated in order to increase thehardness of the surface.

Additionally formed in the hub chuck 238 are first and second beamsprings 386, 388. These beam springs are elongate and include adjacentlydeposed free ends 390, 392 respectively, which form part of the circularbore 378. Free ends 390, 392 have bosses 392, 393 with lead-in chamfers.

The first and second beam springs 386, 388 additionally have fixed ends394, 396 which are secured to the remainder of the chuck 238. As can beseen in FIG. 31a, slots 398, 400 and 402 have been machined or stampedor otherwise formed into the chuck 238 in order to define the first andsecond beam springs 386, 388.

FIG. 31a further depicts mounting holes such as mounting holes 404 whichare used to mount the chuck 238 to the hub. The chuck 238 is retainedbetween the hub 104 and magnetic coupling armature 244 (FIG. 10) with,in a preferred embodiment, rivets or an adhesive bonding. Furtherbalancing holes 406 are provided in the chuck 238 in order to balancethe material removed to form the first and second beam springs 386, 388.In the embodiment shown in FIG. 31a, it is evident that the first andsecond datum 382, 384 and the free ends 390, 392 of the first and secondbeam springs 386, 388 form a triangle and thus essentially three pointsfor holding the chuck onto the spindle of the spindle motor. The lead-inchamfers assist in guiding the chuck 238 onto the spindle of the spindlemotor as the motor is lifted into engagement with the cartridge. Aspreviously indicated, as the spindle of the spindle motor engages thechuck 238, the hub and particularly ring 255 thereof, is first pushed upagainst the inside top of the cartridge against a ring 257 which wasdownwardly dependent from the inside surface of the upper half 80 of thecartridge housing. When the hub comes in contact with the ring 257 thisprevents the hub and disk from becoming cocked or skewed in thecartridge and thus prevents the disk from touching the inside of thehousing, potentially damaging the disk. Substantially simultaneously thespindle shaft penetrates the chuck, the hub is pulled down on thespindle motor by the hub clamp magnet and the spindle motor stopsagainst the underside of the base plate.

Cartridge Door Spring Retention and Stiffening Mechanism

As previously indicated, it is important that the cartridge door 68 beprovided in the appropriate open position and preferably moved to anopened position which is 90 degrees from the closed position in orderthat the door does not interfere with the positioning of the actuatorarm and the heads past the door 68 through the port 76 (FIG. 25) formedin the front of the cartridge 52 preparatory to unloading the heads ontothe disk. In order to accomplish this, the door must be made as thin aspossible so that the effective opening of the port 76 can be as large aspossible and the door must be made in a manner so that it will not bowin the open position again in order to maximize the effective opening ofthe port 76. Further, it is necessary that whatever mechanism is used tobias the door to a closed position not interfere with the effectiveopening of the port 76.

To accomplish these objectives, the present invention provides for thepositioning of a torsion spring 412 in a groove 414 molded into thedoor. The groove is sufficiently large in order to allow the torsionspring 412 to be freely placed therein. The back of the door 68 includesa recess 416 which is designed to receive a stiffening plate 418 with astiffening lip 417, which in a preferred embodiment is comprised of ametallic material with the door in a preferred embodiment comprised of aplastic material including polycarbonate. The stiffening plate 418 isadhered to the door with an appropriate bonding agent well known in thetrade. Not only does the stiffening plate 418 retain the torsion spring412 in the groove 414, but additionally it stiffens the door 68 so thatit does not bow in the middle, interfering with the placement of theheads inside the cartridge relative to the disk.

As can be seen in the figures and in particular, FIGS. 24 through 27,the portion of the torsion spring 412 which is located in the door 68 issubstantially L-shaped and can twist in the groove in order to storeenergy as the door is urged to an open position as shown in FIG. 25. Thestored energy is used to close the door during the removal of acartridge from the drive.

The other end of the torsion spring is additionally L-shaped and isretained in the cartridge housing itself. This retention is accomplishedby a capture cavity 420 which is formed in the upper half 80 of thecartridge and a key 422 which is formed in the lower half 82 of thecartridge. When the upper half and the lower half are mated, the torsionspring is captured between the capture cavity 420 and the key 422 asshown in FIG. 25. FIG. 26 depicts the torsion spring 412 in a restposition (dotted lines) and in a position where it has been twisted(solid lines) in order to store energy as the door is opened. Further,FIGS. 24 and 27 show the main portion of the cartridge door 68 alongwith the cam or tab 74 and the pivot shaft 75.

Imbedded Servo System with Servo Address Mark with Robustness in thePresence of Media Defects

The disk of the present drive is configured in a preferred embodimentinto fifty-six wedges, each wedge having a servo field (with servopattern 500) and with a data field on each side of the servo field. Ofthese wedges, one is an index wedge with fifty-five being non-indexwedges. In order to provide for 40 megabytes of information on the disk,the disk among other things has approximately 1028 tracks or cylinders(average track pitch 1600 TPI) on each of the surfaces. Each track isdivided into a first and a second band as shown in FIG. 33. FIG. 32shows the write current waveform which is used in order to place headcentering servo information in the servo fields of each wedge of eachtrack. The write current provides for a direction of magnetization ortransition as shown in FIG. 33.

The possible transitions in the servo patterns caused by the writecurrent are 312.5 nanoseconds apart. This results in a 3.200 megahertzclock which is the servo clock. This frequency assumes a rotation of3246.7532 revolutions per minute or a rotational period of 18.4800milliseconds. This gives 59,136 servo clocks (SCLKS) per revolution. Aseach revolution is divided into fifty-six wedges, each wedge has 1056servo clock periods with 932 SCLKS for the data fields and the rest forthe servo fields.

The head centering information ("analog") section which is depicted inFIG. 33 (506 in FIG. 34a) of the servo field accounts for headcentering. The analog section has four types of bands. These includeeven.0, even.5, odd.0 and odd.5 bands. The bands for track zero andtrack one are depicted. Track zero, being an even track, has bands 0.0and 0.5 and track one being an odd track, has bands 1.0 and 1.5 (FIG.33). The head centering information 506 is thirty-two SCLKS periods longwith a pattern of eight SCLKS long which repeats four times during theanalog section. There are two periods of "A" transitions followed by twoperiods of "C" transitions which are followed by two periods of "B"transitions followed by two periods of "D" transitions. Throughappropriately circuitry known in the art, the "A" and "B" transitionswhich straddle track zero are read, amplified and compared in order todetermine where the head or transducer is relative to track zero and toadjust the position of the head relative to the track zero. With respectto track one, the "A" and "B" transitions are read and compared in orderto determine where the head is with respect to track one and toreposition the head with respect to track one. The same procedure isused in order to center and adjust the head relative to any track on thedisk.

    ______________________________________                                        Type of Band:                                                                 ______________________________________                                        EVEN.0         A     C                                                        EVEN.5               C          B                                             ODD.0                           B   D                                         ODD.5          A                    D                                         ______________________________________                                    

Further it is noted that a zoned recording scheme is used with lowerdensity recording on the outer tracks and higher density on the innertracks. The servo fields from are radially aligned track-to-track due tothe fact that the placement of the servo fields can be adjusted as eachservo field is located between first and second data fields associatedwith and located on each side of each of the servo fields.

In the present removable cartridge disk drive and also in fixed diskdrive, the servo fields share the same disk surfaces as user datafields. Servo patterns 500 are regularly spaced around the disk withspace for user data in between. These servo patterns 500 include a servoaddress mark (SAM) 502. This is a pattern that cannot occur in the userdata fields or in the remainder of the servo pattern. Detectioncircuitry in the drive recognizes the SAM 502 and synchronizes to it sogates may be opened at appropriate time intervals in order to samplehead centering information and track number information and therebyderive head position information from the remaining part of the servopattern.

As can be seen in FIG. 34, the servo pattern 500 includes the automaticgain control (AGC) pattern 504, followed by the SAM 502 which isfollowed by the head centering information 506 and the track numberinginformation 508. The AGC 504 has a transition at each interval.

The track number information field 508 is encoded in all 11-bit graycode. Two SCLK periods are used for each bit of gray code. A transitionis in the first period if the gray bit is a 1 and the transition is thesecond period if the gray bit is a 0. The most significant bit (G10) isfirst and the least significant bit (G0) is last in time. The binarytrack number determines the gray code bits by the following rule. Gn isthe exclusive "or" of Bn with Bn+1 where Gn is the nth gray bit code andBn is the nth bit of the binary track number and Bn+1 is the next moresignificant bit of the binary track number. B11 is assumed to be 0.

Most if not all embedded servo disk drives have servo address marks.These SAMs use a gap which is longer than any that can occur in normaluser data fields. In many drives as in the present device, after a SAMis detected, the drive uses a timer (counter) to wait until it is almosttime for the next SAM before the drive starts looking for the next SAM.

The present invention uses a novel SAM in order to provide forrobustness in the presences of holes in the magnetic recording material(media defects). These holes can look like SAMs. Thus, an object of thisinvention is to make a SAM 502 that is distinguishable from mediadefects and detectable in the presence of media defects.

This invention uses information about polarity of the detectedtransitions 510 and two main gaps 514, 516 of different lengths that areeach generally longer than media defects. Every transition 510 is theopposite polarity of the one before it. In the servo pattern 500magnetic transitions are only allowed at regularly spaced intervals 512or multiplies of such intervals 512. But not every possible interval hasa transition. In a preferred embodiment, in the area before and afterthe SAM 502, that is in the AGC area 504 and the head centeringinformation area 506, two transitions that are an even number ofintervals away from each other are of the same polarity. Further, anytransitions that are located an odd number of intervals apart are of theopposite polarity. The place where this predefined "rule" is violated isin the SAM 502. It is also noted that the "rule" is violated in thetrack number information area 518 (grey code area) but that this is ofno concern as it is several microseconds from the SAM and is locatedafter the SAM is detected and synchronization to the SAM has beenaccomplished.

If a media defect wipes out transitions in the region before or afterthe SAM 502, the resulting gap in transitions will not look like a gapin the SAM 502 because of the polarity of the pulses read around thedefect gap will not match the polarity of pulses read around a gap inthe SAM in accordance with the above established "rule".

The SAM 502 of a preferred embodiment of the invention, is fourteenintervals wide and has two major gaps 514, 516. Gap 514 is fourintervals long and gap 516 is eight intervals long. In addition, thereis a gap 518, one interval in length, between gaps 514 and 516. Thetransitions around each main gap 514,516 are an even number of locationsapart from each other. This is to make the magnetic transitions aroundthe main gap 514, 516 violate the transition polarity "rule" establishedabove. Also two main gaps 514, 516 have different lengths so said gaps514, 516 do not look alike. This further adds to the robustness andreduces the possibility of falsely detecting a SAM.

In viewing FIG. 35a, it can be seen that in a preferred embodiment, inthe AGC 504 that the transitions alternate between positive and negativepolarity. In the AGC 504, thus the rule that transitions of the samepolarity are spaced even intervals apart (2, 4, 6, etc.) and thattransitions of different polarity are spaced odd intervals apart (1, 3,5, etc.) is maintained. Further, in the area of the head centeringinformation 506 as can be seen partially in FIG. 35 and also in FIG. 34,the "rule" as defined for the AGC area 504 is also maintained. In thearea of the SAM 502, this rule is not maintained. As indicated above,the SAM is fourteen intervals long. A SAM has four transitions. Thefirst transition is identified by the number 520 and is of negativepolarity in the example of FIG. 35a. It is also to be understood thattransition 520 could be of position polarity with the other transitionsaccordingly change to the opposite of what they are presently denoted inFIG. 35.

The second transition 522 in the SAM 502 is of positive polarity and islocated, as indicated above, four intervals from the first transition520. Thus, as transitions 520 and 522 are of differing polarity, and asthey are spaced an even number of intervals apart, they violate the"rule" established for the AGC and the head centering information.Transition 522, as can be seen in FIG. 35a, is located between thefourth and the fifth interval of the SAM 502.

The third transition 524 is of negative polarity and is located betweenthe fifth and the sixth interval of the SAM as is shown in FIG. 35a. Thefourth transition 526 of the SAM is located eight intervals from thethird transition 524. The fourth transition 526 is of positive polarity,thus violating the "rule" of the AGC that an odd number of intervals isto be located between transitions (transitions 524, 526) of differentpolarities.

A transition detector, such as by way of example, a pulse read detectorwith a hystersis comparator, can then decide if it has seen (1) a SAM ifit sees the first main gap 514 or the second main gap 516 or (2) thelong gap that results from a media defect which wipes out transitions.

As can be seen in FIG. 35b, the SAM detection routine is depicted. ThisSAM detection routine includes a first step, presented by block 530, ofproviding a counter for counting from the last identified SAM andbeginning to look for the next SAM just before the counter indicatesthat the appropriate number of intervals or the appropriate amount oftime has passed and thus that the next SAM should be appearing. Once acounter has indicated that the next SAM should be appearing, a detector(block 532), for example the detector of the variety describedhereinabove, begins to detect the presence of and polarity of thetransitions. Simultaneously, the intervals between the transitions arecounted (block 534) and an association is made and stored between thecount of the intervals and the polarity of the transitions (block 536).This association is compared with the known pattern for the AGC, the SAMand the head centering information (block 538). It is to be understoodthat such a detection scheme can be implemented with detection hardware,counters and the like which are well known in the art.

Embedded Servo System With Repetitive Runout Correction

On disk drives, such as drive 50, the recording and playback heads ortransducers must follow nominally circular tracks with great precision.Imbalance and errors in disk centering and disk tilt, due to thereception of the hub chuck of the cartridge 52 onto the spindle motor,cause these tracks to deviate from being perfectly circular. Imperfectreception of the disk in the plane of the magnetic clamp of the spindlemotor, so that the disk is not exactly centered on the spindle of thespindle motor, causes error known as "once-around" error or runout. Withthis error, the disk can be seen to wobble, in the plane of the magneticclamp, in and out relative to the spindle motor. This once-around errorrepeats once each time the disk revolves one time. Imperfect receptionof the disk so that it is not entirely received in the plane of themagnetic clamp, but is tilted, causes error known as "twice-around"error runout. With this error, the disk can be seen to wobble up anddown relative to the plane of the magnetic clamp. This twice-arounderror repeats twice over one revolutions of the disk. The feedback servoloops reduces the repetitive components, but the degree to which it canreduce such components is limited by structural resonances, samplingrates, and other factors which place limits on servo bandwidth. Thisinvention relates to a technique for correcting for the repeatable(once-around and twice-around) components of disk runout which is notsubject to these limitations. This allows cartridge disk drives toreduce tracking errors to levels similar to fixed disk drives andtherefore to match the track densities and servo performance of fixeddisk drives. This novel aspect as well as the other novel aspects ofdrive 50 and cartridge 52 allow the disk to contain 40 megabytes ofinformation and greater amounts (with 1600 TPI and greater) in the abovespecified 21/2 inch form factors.

Embedded servo cartridge disk drives have a servo system which correctsfor both repeatable and non-repeatable tracking errors. Non-repeatabletracking errors (or runout) are caused by such factors as non-repeatablebearing runout, random external force disturbances on the actuator, andrandom external forces applied to the disk drive. Repeatable runoutoccurs as a result of repeatable bearing runout, imbalance of therotating hub assembly and disk, and disk clamping errors. The latter iscomposed of both of the above centering and tilt components which giverise to repeatable tracking error components at once the rotationfrequency (once-around error) and at twice the rotation frequency(twice-around error). Despite great efforts to minimize these errorsmechanically, disk clamping errors are usually quite large in cartridge(removable media) disk drives. This error component is usually notpresent to any significant degree in fixed (non-removable media) diskdrives.

Tracking errors which repeat cannot be adequately attenuated usingclassical feedback servo approaches in cartridge disk drives with highertrack densities. Thus, the use of a classical servo approach can place afundamental limit on drive performance by limiting the number of trackswhich can be squeezed on each disk, while still allowing adequatemargins for tracking error. Fixed disk drives do not have this problemas the media is clamped in place prior to writing servo information andis never removed or shifted on the spindle.

This invention takes advantage of the repeatable nature of thesetracking errors to suppress these components on removable drive tolevels where, after normal feedback servo correction, the servo trackingerrors are as low as on fixed disk drives. The net result is reducedtracking error and the achievement of fixed drive performance on aremovable cartridge disk drive.

This invention uses a microprocessor to analyze and produce a correctionfunction for the repeatable components of the tracking error. Thiscorrection is done independently of the feedback servo loop andminimizes the tracking error which the servo loop must attenuateresulting in better overall tracking accuracy. Since this technique usesfeedforward instead of feedback correction, it is not limited by factorswhich traditionally limit the performance of closed loop feedback servosystems such as structural resonances, sample rate limitations, andother dynamic stability constraints, and allows for performance levelssimilar to fixed disk drives.

At power on, when the cartridge is changed, and at times during normaloperation (such as for example, when the disk drive temperature risesresulting in weaker magnetic fields in the voice coil actuator motor,and thus resulting in the requirement for greater actuating currentsfrom the servo system 550), the repeatable runout of the disk isanalyzed by a microprocessor using Fourier Transform techniques, and ina preferred embodiment, Discrete Fourier Transform (DFT) techniques. Theerror is decomposed into real and imaginary parts which represents bothamplitude and phase information of once-around and twice-aroundrepeatable tracking error components. These correspond to two frequencybins of a DFT, which in this embodiment occur at about 60 Hz(once-around errors) and 120 Hz (twice-around errors). Based on this, acorrection function table or alternatively, a runout error correctionsignal table is generated and stored in RAM and is used to outputcorrection forces to the actuator independent of the action of theclosed-loop feedback servo system. In this way the repeatable componentsof runout are reduced to levels similar to a fixed disk drive evenbefore the action of the closed-loop feedback servo system. The residualerrors which the closed-loop servo system is left to act upon and reduceare now the same for a cartridge disk drive as for a similar fixed diskdrive. This eliminates the servo tracking error disadvantage otherwiseinherent in cartridge verses fixed disk drives and which can limit therelative overall capacity and performance of cartridge verses fixed diskdrives.

FIG. 36 shows an overall block diagram of the servo system 550. Amicroprocessor 552 is used to implement feedback servo loopcompensation. (This could also be implemented by a microprocessor alongwith external compensation components, or entirely with externalcompensation as is known in the art).

The block 562 labeled "Repeatable Tracking Error Correction" is the newelement introduced by this invention. A microprocessor (which in thiscase can be the same microprocessor used for feedback servo loopcompensation) is used to analyze and perform a Fourier Transform, and ina preferred embodiment, a Discrete Fourier Transform (DFT) on theposition error signal (PES) during initial startup and subsequentcalibration periods. The index and servo sector reference signalsprovide the timing information needed to do the DFT and the inverse DFT.Once the repeatable error components have been analyzed and stored, aninverse DFT is performed at each servo sector and a feedforwardcorrection signal is generated and output to the actuator driver inaddition to, and independent from, the control signal generated by thenormal feedback servo loop compensation.

More specifically, the schematic FIG. 36 depicts a servo system 550 ofthe invention which includes both a feedback loop 551 and a feedforwardline 553. Feedback loop 551 includes an microprocessor 552 whichprovides for the feedback servo loop compensation calculation.Additionally, feedback loop 551 includes summing point 554, actuatordriver 556 and the actuator (for example a voice coil motor) 558 whichcauses the head to seek to the actual desired position. The signal fromthe actuator 558 is then feed back to a summing point 560 which sums theactual position of the head as implemented by the actuator 558 and asdetermined by the head in reading the servo patterns on the disk and thedesired position signal. The error signal is then provided to themicroprocessor 552 which outputs an appropriate correction signal,generally as a current in order to drive the actuator driver 556.

The feedforward compensation for correcting for repeatable track erroris performed by the microprocessor 562. As indicated above, in apreferred embodiment, the functions of the microprocessor 560 and of themicroprocessor 552 are performed by the same microprocessor at differenttimes.

With respect to the feedforward line 553, it is highly advantageous toinitially drive the actuator as close as possible to the desiredlocation before attempting to correct the location with feedback servoloop compensation. Accordingly, the feedforward compensation afforded bymicroprocessor 562 provides a feedforward correction signal to summingpoint 554, which in combination with the feedback correction signal frommicroprocessor 552, provides a current to the actuator driver 556 inorder to drive and position the actuator 558. The microprocessor 562creates and stores a runout table as described in FIGS. 37a through 37din order to apply the runout correction. With inputs including an indexreference and a sector reference, in addition to input from the summingpoint 560 over line 561, the repeatable tracking error correctionmicroprocessor 562 in conjunction with building the runout table, canprovide a current signal to summing point 554 in order to drive theactuator 558. It is noted that line 561 is used to make measurements inorder to build the runout table, and that after the table is built, thatmicroprocessor 562 can disable this line.

FIGS. 37a-37d are flow charts of the microprocessor firmware (Exhibit Ais a copy of the firmware code listing) used to perform the DFT on therepeatable runout during calibration time, generate the correctionfunction and to do the inverse DFT as part of the processing to generatea runout table for the error correction signal.

During the calibration phase the once-around and twice-around runoutsare measured by doing the DFT at each servo sector or "wedge". In thepresent embodiment, there are 56 servo sectors (one index sector and 55non-index sectors). These runout measurements are converted to frequencydomain measurements by the DFT which resolves the measurement into realand imaginary parts containing both amplitude and phase information ofthe once-around and twice-around components of runout tracking error.These are stored in the microprocessor 562 as oncereal (once-around realcomponents), onceim (once-around imaginary components), twicereal(twice-around real components) and twiceim (twice-around imaginarycomponents).

Runout tables (stored in RAM for example) are then generated bymultiplying the DFT by a complex number which takes into account theactuator characteristics and amplifier gains so as to correct for themeasured repeatable runout error when applied to the actuator as anindependent forcing function. These forcing functions are stored asL1RE, L1IM, L2RE, and L2IM which are DFT representations of theonce-around and twice-around runout correction functions (FIG. 37d).Disk clamp centering, disk tilt, disk thickness, and actuator geometriesmake the repeatable runout errors dependant on the position in theactuator stroke and on which surface of the disk is being used. For thisreason a different table is generated for each surface. A correctionfunction is also applied which is dependant on the track number andwhich compensates for variations in geometries between the disk and theactuator over the stroke. This is the variable "target" in the flowchartwhere target is dependant on position in the stroke and represents thedesired track.

Specifically referring to the flow charts in FIGS. 37a through 37d, apreferred embodiment of the invention is implemented as follows.

In FIG. 37a, the overall structure of the process performed by themicroprocessor 562 is set out. In this structure 570, the operation isinitiated by setting all variables equal to zero. The variables include"L" which is the number of sectors, which in a preferred embodiment, is56. The variables also include the once-around real (ONCEREAL) componentof the complex number performed by the Fourier Transform and theonce-around imaginary (ONCEIM) component of the Fourier Transform. Theseare set to zero in block 574. The next variables which are set to zeroare the twice-around real component (TWICEREAL) of the Fourier Transformand the twice-around imaginary component (TWICEIM) of the FourierTransform. Then measurements are taken at every servo sector until thelast servo sector (LMAX) is measured at block 578. Thus, structure 570of FIG. 37a indicates that structure 580 of FIG. 37b should be performed56 times or LMAX times.

For each servo sector (i.e. at each of the 56 wedges described in apreferred embodiment about the disk) a once-around and twice-aroundrunout measurement is made by the microprocessor 562 according to thestructure 580 (FIG. 37b). In structure 580, block 582 includes a counterfor stepping between successive wedges in order to perform themeasurements. Block 584 includes a measurement and calculation for theonce-around real component of the runout error. In this block 584, theonce-around real component is equal to the previously calculatedonce-around real component for the particular track on which thespecific servo section or wedge is located, plus the position errorsignal (PES) times the COS (K') where K' is equal to 2πK/N.

The DFTs are listed below with F₁ for the once-around errors (about 60Hz) and F₂ for the twice-around errors (about 120 Hz). It is the COSportion of F₁ that is performed in block 584. ##EQU1## where M=number ofmeasurements per revolution of the disk

N=number of the wedges

M=2N

K=the number of wedges (integers 0, 1, 2, 3 . . . )

Block 586 calculates the imaginary component of the once-around runoutcorrection in the same manner except that SIN (K') (the Sin portion ofF₁) is utilized. As with block 584, block 590 calculates thetwice-around real component of the runout error by adding the previouslycalculated runout error for the other subsequent wedges in the track tothe position error signal, PES, times COS (K') (which symbolicallyrepresents the COS portion of F₂). Similarly block 592 performs the samecalculation with the position error signal multiplied by the SIN (K')(which symbolically represents the Sin portion of F₂). The structure 580is then performed for each servo on the track and a summation of all ofthe runout correction errors is made so that for each track there is aonce-around real value, a once-around imaginary value, a twice-aroundreal value, and a twice-around imaginary value.

In FIG. 37c, complex correction functions, including real and imaginaryparts, are generated based on the measure runout structure 580 of FIG.37b. In FIG. 37c, the runout adaptive structure 600 is performed byfirst clearing all of the variables in block 602 and then having thehead actuated to an outer track as provided for by block 604. The outertrack can be an outer most track or a track which is outwardly of aninner track which is specified in block 62. Block 606

that the measure runout structure 580 of FIG. 37b is then implemented inorder to provide the four complex values for each track which arecalculated by the structure 580. Once these values are calculated, thenthe function of block 608 is implemented. In block 608 for the outertrack, a once-around real correction function is generated andthereafter stored in block 620 under the value M1RE. The outeronce-around real correction function (OUT1RE) in block 608 is generatedby adding any previous once-around outer correction function for thattrack to the sum of the once-around value calculated in block 584 timesa constant K1REAL minus the once-around imaginary value calculated inblock 586 times a constant M1IM. The constant M1REAL and M1IM depend onthe characteristics of the drive as outlined above. These values, aswell as K2REAL and K2IM listed below, can be calculated from knownmathematical relationships for the drive configuration, but practicallythey are empirically determine with an emulator as is known in the art.The OUT1RE function can be performed as many times as desired for eachtrack and summed in order to increase the accuracy for the final OUT1REvalue for each track.

Similarly an outer track once-around imaginary function (OUT1IM) iscalculated in block 608 and this value is stored in block 620 as M1IM.In block 610, twice-around real and imaginary correction functions forthe outer track (OUT2RE, OUT2IM) are calculated and stored respectivelyas M2RE and M2IM in block 620. In block 610, the functions calculated inthe structure of 580 in FIG. 37b are multiplied by the constant K2REALand K2IM, which again are constant values determined by the specificstructure of the disk drive as set out above. In block 612, the head isactuated to a track which is inwardly of the track measured in block604, and then in block 614, the runout algorithm of structure 580 isperformed on the inner track. Block 616 and 618 are similar to block 608and 610, but are performed for the inner track. These blocks result inthe storing of values in blocks 620 which include B1RE, B1IM, B2RE andB2IM, which stand for inner track once-around real and imaginarycorrection functions and inner track twice-around real and imaginarycorrection functions, respectively.

It is to be understood that the value of block 620 can be computed andstored in complex, slope-intercept form in order to simply thecalculation of the flow charts of FIGS. 37a-32d as is known in the art.

It is also to be noted that alternatively instead of making calculationsfor an outer track and an inner track and then scaling between saidtracks as set forth in FIG. 37d (blocks 632, 634) that the measurementfor a single track can be made for block 620 and then other values forblocks 632, 634 can be scaled from the values for the single track.

A structure 630 shown in FIG. 37d then makes the correction functionswhich are complex values having real and imaginary components of blocks620 and builds a runout table for each track on the disk. It is to beunderstood that alternatively, instead of building a runout table thatit is possible to have the calculations contemplated in FIG. 37d done inreal time and on the fly. The runout table of FIG. 37d is constructedfor each individual track and each individual sector on the track. Inblocks 632 and 634 the once-around real and imaginary components andtwice-around real and imaginary components are calculated for each trackand each sector on the track by scaling between the values of the innertrack and the outer track or by scaling from a single track, preferablya middle track, as calculated in the runout adaptive structure 600 inFIG. 37c. As can be seen block 632 for the once around real componentfor any particular track and sector, this is calculated by multiplyingthe once-around real component of the correction factor as stored inblock 620 by the target which is a mathematical representation of thetrack and sector and adding thereto a base value which is the realcomponent of the correction function stored in block 62 for the innertrack. In other words, the base value is the inner track value andthereto is added a scale mount which is equivalent to a portion of theouter value in order to calculate the value for a track which fallsbetween the correction function for the inner track and the outer track.The same process is accomplished for the imaginary once-around componentin block 620. Similarly, the same scaling function is accomplished forthe twice-around real and imaginary components for each sector in eachtrack by block 634. Block 638 emphases that the calculations of block632 and 634 are accomplished for each of the sectors in each track.Again, scaling can occur from a single, preferably, middle track, ifdesired.

In blocks 640 and 644, the inverse of the discrete Fourier Transform isperformed in order to transform the correction functions of blocks 632,634 for each sector on each track into, in a preferred embodiment, acurrent signal to be provided to the actuator driver 556 in FIG. 36.Blocks 640 and 644 cause the runout table to be generated. This isaccomplished by adding the once-around current value as calculated inblock 640 to the twice-around current value as calculated in block 644.In block 640, the value which is denoted by FEED(L) is equivalent to thecomplex value L1RE calculated in block 632 times the COS (K') (which issymbolically used to represent the inverse DFT) in order to perform theinverse Fourier Transform as previously discussed. To this value isadded L1IM times SIN(K') (which is symbolically used to represent theinverse DFT). In block 644, the twice-around correction functions L2REand L2IM are used in the same manner as the once-around correctionfunctions are used in block 640, in order to calculate the errorcorrection signal which is a combination of the FEED(L) value calculatedin block 640 plus that calculated in block 644 for each sector on eachtrack. These calculations result in runout tables of current valueswhich are used to drive the actuator 558.

Limited Copyright Waiver

A portion of the disclosure of this patent document (Exhibit A, CodeListing) contains material to which the claim of copyright protection ismade. The copyright owner has no objection to the facsimile reproductionby any person of the patent document or the patent disclosure, as itappears in the U.S. Patent and Trademark Office file or records, butreserves all other rights whatsoever.

Copyright 1991 Iota Memories Corporation

Industrial Applicability

The operation of the disc drive 50 and removable cartridge 52 of theinvention are as disclosed hereinabove. From the above, it is evidentthat the present invention provides for a disk drive and cartridge whichfits into the 21/2 inch disk, 17.5 millimeter high drive housing formfactor and affords a storage capacity per cartridge of at least40-megabytes. The present invention provides for reduced powerconsumption and safety interlocking mechanisms to prevent damage to thedrive and cartridge, and also infinite storage capabilities.

Other aspects and objects of the invention can be obtained from a reviewof the appended claims and figures.

It is to be understood that other embodiments of the present inventioncan be fashioned and come within the spirit and scope of the inventionas claimed.

What is claimed is:
 1. An integral apparatus for a disk drive which hasa transducer mounted onto a movable actuator arm which disk drive isadapted for receiving a removable cartridge having a door which ispositionable in an open and in a closed position and containing a diskfor storing data, comprising:an integral member having: means adaptedfor selectably ensuring that the door of the cartridge is properlyopened should the door position reach a predefined threshold and forpreventing the further reception of the cartridge into the disk driveshould the door position not reach the predefined threshold; and rampmeans for receiving the actuator arm in order to ramp the transducer offof the disk; and means adapted for holding an air filter for filteringair that flows past the disk.
 2. The integral apparatus of claim 1including:said ensuring means and said ramp means are integral onto aprojection which extends from the air filter holding means.
 3. Theintegral apparatus of claim 2 including:said projection is bifurcatedinto a first end and a second end which is spaced from the first end;said first end includes said ensuring means and the second meansincludes the ramp means.
 4. The integral apparatus of claim 3including:said ensuring means includes a door stop integral with a doorramp, said door stop for preventing the further reception of thecartridge into the disk drive should the door position not have reacheda predefined threshold and the door ramp for urging the door from thepredefined threshold.
 5. The integral apparatus of claim 4including:said door stop includes a stop surface which is substantiallyperpendicular to the direction of travel of the cartridge into the diskdrive and the door ramp includes a ramped surface which extendsrearwardly and outwardly of the stop surface.
 6. The integral apparatusof claim 3 including:said first end is disposed substantially parallelto the direction of reception of the cartridge; and said second end isdisposed substantially perpendicularly to the actuator arm with theactuator arm received on the ramp means.
 7. The integral apparatus ofclaim 3 including the disk drive has an actuator for moving the actuatorarm substantially radially across the disk, said integral member furthercomprising:said first end is disposed substantially parallel to thedirection of reception of the cartridge; and said second end is disposedsubstantially perpendicularly to the actuator arm with the actuator armreceived on the ramp means.
 8. The integral apparatus of claim 1including:said ensuring means includes a door stop integral with a doorramp, said door stop for preventing the further reception of thecartridge into the disk drive should the door position not have reacheda predefined threshold and the door ramp for urging the door from thepredefined threshold.
 9. The integral apparatus of claim 8including:said door stop includes a stop surface which is substantiallyperpendicular to the direction of travel of the cartridge into the diskdrive and the door ramp includes a ramped surface which extendsrearwardly and outwardly of the stop surface.
 10. The integral apparatusof claim 1 further including:a curved air filter with a concave surfaceand a convex surface; said means adapted for holding said air filteradditionally for directing the concave surface toward the cartridge. 11.The integral apparatus of claim 1 further including:means for absorbingenergy from an uncontrolled unloading of the actuator arm onto the rampmeans.
 12. The integral apparatus of claim 11 further including:saidenergy absorbing means mounted onto the integrated member adjacent tothe air filter holding means and distally from said ramp means.
 13. Theintegral apparatus of claim 1 including:said integral member includes ameans for diverting the flow of air from the area of the disk toward thefilter.
 14. The integral apparatus of claim 13 including said divertingmeans includes:a planar member which extends toward and in the plane ofthe disk.
 15. The integral apparatus of claim 1 with the actuator armhaving an element extending outwardly of the transducer, said apparatusfurther including:said ramp means located on the integral onepiecemember so as to be adapted to engage the element extending outwardly ofthe transducer.
 16. The integral apparatus of claim 1 furtherincluding:said integral member includes an electro-static dischargedrain.
 17. The integral apparatus of claim 1 further including:saidintegral member being comprised of a material that allows the integralmember to be an electro-static discharge drain.
 18. An integralapparatus for a disk drive which has a transducer mounted onto a movableactuator arm which disk drive is adapted for receiving a removablecartridge having a door which is positionable in an open and in a closedposition and containing a disk for storing data, comprising:an integralmember having: means adapted for selectably ensuring that the door ofthe cartridge is properly opened should the door position reach apredefined threshold and for preventing the further reception of thecartridge into the disk drive should the door position not reach thepredefined threshold; and ramp means for receiving the actuator arm inorder to ramp the transducer off of the disk.
 19. The integral apparatusof claim 18 including:said ensuring means and said ramp means areintegral onto a projection which extends from a base.
 20. The integralapparatus of claim 19 including:said projection is bifurcated into afirst end and a second end which is spaced from the first end; saidfirst end includes said ensuring means and the second means includes theramp means.
 21. The integral apparatus of claim 20 including:saidensuring means includes a door stop integral with a door ramp, said doorstop for preventing the further reception of the cartridge into the diskdrive should the door position not have reached a predefined thresholdand the door ramp for urging the door from the predefined threshold. 22.The integral apparatus of claim 21 including:said door stop includes astop surface which is substantially perpendicular to the direction oftravel of the cartridge into the disk drive and the door ramp includes aramped surface which extends rearwardly and outwardly of the stopsurface.
 23. The integral apparatus of claim 20 including:said first endis disposed substantially parallel to the direction of reception of thecartridge; and said second end is disposed substantially perpendicularlyto the actuator arm with the actuator arm received on the ramp means.24. The integral apparatus of claim 20 including the disk drive has anactuator for moving the actuator arm substantially radially across thedisk, said integral member further comprising:said first end is disposedsubstantially parallel to the direction of reception of the cartridge;and said second end is disposed substantially perpendicularly to theactuator arm with the actuator arm received on the ramp means.
 25. Theintegral apparatus of claim 18 including:said ensuring means includes adoor stop integral with a door ramp, said door stop for preventing thefurther reception of the cartridge into the disk drive should the doorposition not have reached a predefined threshold and the door ramp forurging the door from the predefined position.
 26. The integral apparatusof claim 25 including:said door stop includes a stop surface which issubstantially perpendicular to the direction of travel of the cartridgeinto the disk drive and the door ramp includes a ramped surface whichextends rearwardly and outwardly of the stop surface.
 27. The integralapparatus of claim 18 further including:means for absorbing energy froman uncontrolled unloading of the actuator arm onto the ramp means. 28.The integral apparatus of claim 27 further including:said integralmember having a means adapted for holding an air filter for filteringair that flows past the disk; and said energy absorbing means mountedonto the integral member adjacent to the air filter holding means anddistally from said ramp means.
 29. The integral apparatus of claim 18with the actuator arm having an element extending outwardly of thetransducer, said apparatus further including:said ramp means located onthe integral member so as to be adapted to engage the element extendingoutwardly of the transducer.
 30. The integral apparatus of claim 18further including:said integral member includes an electro-staticdischarge drain.
 31. The integral apparatus of claim 18 furtherincluding:said integral member being comprised of a material that allowsthe member to be an electro-static discharge drain.
 32. An integralapparatus for a disk drive which has a transducer mounted onto a movableactuator arm which disk drive is adapted for receiving a removablecartridge having a door which is positionable in an open and in a closedposition and containing a disk for storing data, comprising:an integralmember having: means adapted for selectably ensuring that the door ofthe cartridge is properly opened and for preventing the reception of thecartridge into the disk drive should the door not be properly opened;and ramp means for receiving the actuator arm in order to ramp thetransducer off of the disk; and means adapted for holding an air filterfor filtering air that flows past the disk.
 33. An integral apparatusfor a disk drive which has a transducer mounted onto a movable actuatorarm which disk drive is adapted for receiving a removable cartridgehaving a door which is positionable in an open and in a closed positionand containing a disk for storing data, comprising:an integral memberhaving: means adapted for selectably ensuring that the door of thecartridge is properly opened and for preventing the reception of thecartridge into the disk drive should the door not be properly opened;and ramp means for receiving the actuator arm in order to ramp thetransducer off of the disk.